Testing Principle

The determination of total bile acid(TBA) concentration is based on enzyme cycling method, which allows for the signal amplification through cycled regeneration reactions. In the forward reaction, bile acid molecules are oxidized by thio-NAD+, generating oxidized bile acids and reduced co-enzyme thio-NADH. While in the reverse reaction, the oxidized bile acids are reduced back to bile acids by the excess co-enzyme NADH in the presence of 3-α-hydroxysteroid dehydrogenase(3-α-HSD), and are ready for the next round of forward oxidation reaction. The signal amplification by this enzyme cycling method enables a much more higher detection sensitivity of the test. The concentration of bile acid can be calculated from the rate of thio-NADH formation, which is based on the absorbance detected at 405 nm.  

Product Features

Linearity range: 0 – 180 μmol/L; linear correlation coefficient ≥0.990; linearity deviation is within ±10%.

Absorbance of blank ≤ 0.90

Changing rate of absorbance of blank (ΔA/min) ≤ 0.05

Sensitivity: the difference of absorbance per unit of concentration (ΔA) ≥ 0.30 while testing the specific sample of concentration of 50 μmol/L.

Accuracy: Relative deviation is within ±10%.

Precision: intra assay CV(%) ≤ 5%; inter assay CV(%)  ≤ 6%.

Technical Parameters

Reference range: 2 – 12 μmol/L

Packaging Specification

R1: 1×30 ml, R2: 1×10 ml

R1: 2×30 ml, R2: 1×20 ml

R1: 2×45 ml, R2: 2×15 ml

R1: 2×60 ml, R2: 2×20 ml

R1: 4×60 ml, R2: 4×20 ml

R1: 3×80 ml, R2: 4×20 ml

Calibrator: appendant

Quality control: additional purchase

Storage and Period of Validity

Store the Biomedia TBA test kits at 2 to 8 ℃ protected from light. The period of validity of unopened reagents can be up to 16 months. Opened reagents can be valid for 1 month if stored at 2 to 8 ℃ protected from light.